This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our lab studies fibrosis in airways caused by epithelial injury, which is a common feature of asthma and other diseases. In order to extend our tissue-engineered in vitro models of epithelial scrape injury leading to subepithelial fibrosis, and to develop OCT and MPM as a potential clinical tool for characterizing and monitoring remodeling in airways during fibrotic diseases, we wish to scrape rabbit tracheal epithelium and track short and longer-term (up to 1 week) changes in the subepithelial collagen-rich layer, using endoscopic OCT and conventional MPM. We will also be comparing the mechanical properties of scraped vs. unscraped tracheal mucosa, and correlating changes in the mechanical properties to changes in the collagen and elastin microstructure of the mucosa, as revealed by multiphoton images. All animal studies will be conducted in accordance with approved UCI animal protocol #2007-2754. A copy of the approved protocol and any amendments will be provided to BLI.